The invention relates to a cooling apparatus for power semiconductors, which apparatus is essentially box-shaped and displays two extruded cooling sections that are connected to each other, one cooling section forming a first heat-conducting side wall, and the other cooling section forming a second heat-conducting side wall opposite the first side wall. The side walls display on their inner sides integrated cooling partitions, which bound cooling channels through which a cooling fluid can be conducted. The power semiconductors are to be attached to the outer sides of the side walls in a heat-conducting manner.
The preferred field of application is power converters, in particular inverters.
In one known cooling apparatus of this type (DE 196 28 545 A1), the cooling partitions formed on the opposing side walls abut each other with their free front sides, when the cooling sections are joined to each other. In order to be able to produce the cooling sections from heat-conducting metal in an extrusion process, the cooling partitions must be situated a certain, predetermined minimum distance from each other. Through this factor, the number of cooling partitions, relative to the volume of the cooling apparatus, and thus also the total cooling surface, are limited.
The invention is based on the task of specifying a cooling apparatus, of the type named in the introduction, that ensures an effective cooling with the lowest possible volumes.
According to the invention, this task is accomplished by the fact that the cooling partitions formed on the first side wall extend between the cooling partitions formed on the second side wall.
Achieved in this solution is a smaller spacing between the cooling partitions, relative to the volume of the cooling apparatus, than hitherto. Nevertheless, the cooling sections can, furthermore, be produced with the smallest spacing between their cooling walls that is possible in the extrusion process.
Preferably, the edge regions, facing away from the first side wall, of the cooling partitions formed on the first side wall are pressed into grooves in the second side wall. In this way, the cooling sections can be joined through a simple pressing-together.
Here, the edge regions, facing away from the first side wall, of the cooling partitions formed on the first side wall, can form a bulb. This results in a larger heat-transfer surface between the second side wall and the cooling partitions formed on the first side wall, since the bulb is thicker than other regions of the cooling partition on which it is formed.
Alternatively or in addition, the front sides, facing away from the second side wall, of the cooling partitions formed on the second side wall can display depressions, in which projections formed on the inner side of the first side wall are held fixed. When not only the cooling partitions formed on the first side wall are connected to the second side wall, but also the cooling partitions formed on the second side wall are connected to the first side wall, there results a more solid joining of the cooling sections.
When the projections are produced shorter than the depressions are deep, a compensation for measurement tolerances in the extrusion of the cooling sections is possible.
Preferably, the projections are firmly pressed into the depressions accompanied by reciprocal cold welding. By this means, there results, in a simple manner, a close and secure joining of the cooling sections also on the side of the first side wall.
Preferably, the cooling partitions are provided with cooling ribs. By this means, the effective cooling surface is increased.
Further, the two outer cooling partitions of the cooling partitions formed on the second side wall can form two additional side walls of the cooling apparatus. These outer cooling partitions thus fulfill a double function: on the one hand as a boundary of the cooling apparatus, and on the other hand the removal of heat by conduction.